Frequently Asked Questions

Toilets - Installation

Can I use an in-tank bowl cleaner with my Delta toilet?

No, do not use in-tank bowl cleaners. Products containing chlorine or chlorine-related products can seriously damage fittings in the tank, which can cause leakage and property damage. Delta Faucet Company shall not be responsible or liable for any tank fitting failure or damage caused by the use of in-tank bowl cleaners.

How do I install a Delta toilet?

Detailed instructions for installing a Delta toilet are provided in the Installation Instructions that come with your Delta toilet. These instructions are also downloadable on the product information page for your Delta toilet model (see

I just installed my Delta toilet and it doesn’t flush. What’s the problem?

toilet diagram
If your new Delta toilet doesn’t flush, follow these steps:
  1. Check to see if the rubber band and tag are removed from the seal (flapper) (see item #4 in the illustration).
  2. Reconnect the chain (1) to the trip lever (2) or flush valve flapper (4).
  3. Adjust the chain assembly (1) to remove excessive slack.

My toilet is really loud when the tank is filling. How can I fix this?

If the water pressure to the toilet is too high, you may partially close the water supply shut-off valve. Check the performance of your toilet following any adjustments. If this doesn’t resolve the issue, remove dirt or obstructions from the valve head and flush the lines.

The flush on my Delta toilet doesn’t seem strong enough. How can I fix it?

Depending on the litres per flush (Lpf) of your old toilet, your new Delta toilet may use less water for each flush. High-efficiency Delta toilets are precisely engineered to flush at 4.845 Lpf and are tested to remove 1,000 grams of solid waste as determined by third-party maximum performance (MaP) testing. To ensure your Delta toilet flushes properly, follow these steps:
  1. Adjust the tank water level to match the waterline.
  2. Fully open the water supply shut-off valve.
  3. Clear obstructions from the trapway, jet, or bowl rim holes.
  4. Clear obstructions from the waste line.

The tank on my Delta toilet takes a long time to fill. What’s the problem?

Make sure the water shut-off valve for your toilet is fully open. If this doesn’t resolve the problem, clean the valve inlet, valve head or supply line and flush the lines.

What else do I need to install my Delta Prelude™ toilet?

In addition to the items that came in your Delta toilet box, you will need a supply line to connect the toilet to the water supply shut-off valve and a tube of silicone to help secure the toilet bowl to the floor. You may also want safety goggles, a flashlight to see behind the toilet, and a blanket or other soft surface to set the toilet on while you install the mounting bolts. It’s also a good idea to have someone on hand to help you install the toilet bowl.